feat: add kube_persistentvolume_volume_mode metric

Signed-off-by: Ricardo Lopes <[email protected]>

Author: ricardoapl

docs/metrics/storage/persistentvolume-metrics.md

@@ -11,6 +11,7 @@
 | kube_persistentvolume_created            | Gauge       | Unix creation timestamp                                                                                                   | seconds                 | `persistentvolume`=&lt;persistentvolume-name&gt; <br>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | EXPERIMENTAL |
 | kube_persistentvolume_deletion_timestamp | Gauge       | Unix deletion timestamp                                                                                                   | seconds                 | `persistentvolume`=&lt;persistentvolume-name&gt; <br>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | EXPERIMENTAL |
 | kube_persistentvolume_csi_attributes     | Gauge       | CSI attributes of the Persistent Volume, disabled by default, manage with [--metric-opt-in-list](../../developer/cli-arguments.md))     |                         | `persistentvolume`=&lt;persistentvolume-name&gt; <br> `csi_mounter`=&lt;csi-mounter&gt; <br> `csi_map_options`=&lt;csi-map-options&gt;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | EXPERIMENTAL |
+| kube_persistentvolume_volume_mode       | Gauge       |                                                                                                                           |                         | `persistentvolume`=&lt;persistentvolume-name&gt; <br>`volumemode`=&lt;volumemode&gt;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | EXPERIMENTAL       |
 
 ## Useful metrics queries
 

internal/store/persistentvolume.go

@@ -392,6 +392,30 @@ func persistentVolumeMetricFamilies(allowAnnotationsList, allowLabelsList []stri
 				}
 			}),
 		),
+		*generator.NewFamilyGeneratorWithStability(
+			"kube_persistentvolume_volume_mode",
+			"Volume Mode information for PersistentVolume.",
+			metric.Gauge,
+			basemetrics.ALPHA,
+			"",
+			wrapPersistentVolumeFunc(func(p *v1.PersistentVolume) *metric.Family {
+				volumeMode := ""
+				if p.Spec.VolumeMode != nil {
+					volumeMode = string(*p.Spec.VolumeMode)
+				} else {
+					volumeMode = string("Filesystem") // Filesystem is the default mode used when volumeMode parameter is omitted.
+				}
+
+				return &metric.Family{
+					Metrics: []*metric.Metric{
+						{
+							LabelKeys:   []string{"volumemode"},
+							LabelValues: []string{volumeMode},
+							Value:       1,
+						},
+					}}
+			}),
+		),
 	}
 }
 

internal/store/persistentvolume_test.go

@@ -30,6 +30,7 @@ import (
 
 func TestPersistentVolumeStore(t *testing.T) {
 	iscsiInitiatorName := "iqn.my.test.initiator:112233"
+	volumeMode := v1.PersistentVolumeBlock
 	cases := []generateMetricsTestCase{
 		// Verify phase enumerations.
 		{
@@ -743,6 +744,38 @@ func TestPersistentVolumeStore(t *testing.T) {
 				`,
 			MetricNames: []string{"kube_persistentvolume_csi_attributes"},
 		},
+		{
+			Obj: &v1.PersistentVolume{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-default-volumemode",
+				},
+				Spec: v1.PersistentVolumeSpec{
+					VolumeMode: nil,
+				},
+			},
+			Want: `
+					# HELP kube_persistentvolume_volume_mode Volume Mode information for PersistentVolume.
+					# TYPE kube_persistentvolume_volume_mode gauge
+					kube_persistentvolume_volume_mode{persistentvolume="test-default-volumemode",volumemode="Filesystem"} 1
+				`,
+			MetricNames: []string{"kube_persistentvolume_volume_mode"},
+		},
+		{
+			Obj: &v1.PersistentVolume{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-block-volumemode",
+				},
+				Spec: v1.PersistentVolumeSpec{
+					VolumeMode: &volumeMode,
+				},
+			},
+			Want: `
+					# HELP kube_persistentvolume_volume_mode Volume Mode information for PersistentVolume.
+					# TYPE kube_persistentvolume_volume_mode gauge
+					kube_persistentvolume_volume_mode{persistentvolume="test-block-volumemode",volumemode="Block"} 1
+				`,
+			MetricNames: []string{"kube_persistentvolume_volume_mode"},
+		},
 	}
 	for i, c := range cases {
 		c.Func = generator.ComposeMetricGenFuncs(persistentVolumeMetricFamilies(c.AllowAnnotationsList, c.AllowLabelsList))